MOSCOW (AP) — Nearly 14,500 homes have been flooded in a Russian region bordering Kazakhstan after water levels spiked in a local river, local authorities said Tuesday.

The floods sparked evacuations of thousands in the Orenburg region, located some 1,200 kilometers (745 miles), southeast of the capital, Moscow, after a dam on the Ural River burst last week under the pressure of surging waters.

Water levels in the river have since been fluctuating in different parts of the region, affecting the number of flooded houses.

Experts have cited multiple possible causes of the floods: large snow reserves in the area melting, deep freezing of the soil which doesn’t allow it to absorb rain or melting snow, and a massive release of water from the Iriklinksy reservoir in the eastern part of the region into the Ural River.

Local authorities have classified the deluge as an emergency of federal importance, and more than 16,500 people have been evacuated from the flooded areas, the office of the Orenburg governor said Tuesday.